Hitherto, ethylene homopolymers or copolymers of ethylene and α-olefins have been widely industrially produced with a Ziegler Natta catalyst containing a Ti compound and magnesium compound.
Magnesium chloride and magnesium dialkoxide were used as a support of the catalyst system. In view of process constraints (e.g., powder fluidized drying efficiency) or improvements in catalyst activity and film appearance (e.g., reducing foreign bodies, so-called fish eyes or gel in film) (JP-A-H9-194522), the technique has been widely carried out that the support is mechanically pulverized for use. However the pulverization of support increases an amount of fine powder in polymer powder, which reflects the properties of support particles. The increase causes the trouble of blocking a powder transport line. Further the powder flowability decreases due to the bad powder form, thereby letting a reactor of polymerization unstable.
In view of the above, the invention was made and an object of the invention is to provide a magnesium compound, solid catalyst component, catalyst for ethylene polymerization, and a method of producing an ethylene polymer yielding an ethylene polymer excellent in particle size distribution and flowability of polymer powder without imparting the basic catalyst performance such as activity, hydrogen sensitivity and film appearance.